Fire detector



FIG. 1 is a perspective view of the fire detector embodying the new design;

FIG. 2 is a top view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a right side view thereof; and,

FIG. 6 is a left side view thereof. 

The ornamental design for a fire detector, as shown and described. 